A Spectroscopic Investigation into the Stability of Carbon Dots Derived from Polyethylene Glycol

Carbon dots (CDs) are nanomaterials that have gained worldwide attention due to their unique properties. This study investigated the stability of polyethylene glycol (PEG) CDs over a period of 60 days. To our knowledge, the stability of microwave-synthesized PEG CDs has not been extensively investigated by previous research groups. Comprehensive characterization was conducted using spectroscopic techniques, including UV-Vis, and fluorescence and additional techniques like DLS and TEM. UV-Vis, fluorescence, and DLS analysis were performed at regular intervals (days 1, 15, 30, and 60) to monitor changes in optical properties, particle size, and dispersion. Quantum yield (QY) and lifetime measurements were conducted on day 1 and day 60 to assess the luminescence efficiency. The results demonstrated exceptional stability of the PEG CDs, evident from the consistent UV-Vis, fluorescence spectra, unchanged particle size, and preserved morphology. Moreover, the QY and lifetime values showed small changes, indicating the robustness of the CDs.